Trapezoidal Thread

[Rakesh]

Hi every body,

I am doing Trapezoidal external thread with specifications as 25 mm major dia, 23.5 mm pitch dia, 21.5 mm minor, 30 deg incl angle and 3 mm pitch.

If anybody can help me to calculate to find pin dia and what is dimn of the measurement over pin to check this thread?

Thanks in advance

[Matthew Hajicek - Singularity]

I'd make a line drawing, create an arc tangent for the pins, and measure from the geometry.

[pip]

wasnt there a small program on the FTP for this..

[strabe]

Rakesh,

 

The closest thing I have is a one wire formula for Acme threads which are 29° included. .4872 X P = wire size. (Where P = linear pitch) That's all I have. Hope it helps.

 

:Edit: I have this formula but not one to make a measurement over the wire, sorry. FWIW There's more formulas for measuring Acme threads in the Machinery's Handbook but again, I don't know if these will get you close enough for what you're doing.

 

Ken